Waterproofing masonry structure



IN VENTOR Arf/7W A. Johnson. BY #Za/ ATTORNEYS A. A. JOHNSONWATERPROOFING MASONRY STRUCTURE Flled May 24, 1953 Nl mi MwCOb Nov. 17,1936.

atented Nov. 17, 1936 iTED STATES PATENT FC'E Arthur A. Johnson, GreatNeck, N. Y., assignor to Johnson-March Corporation, a corporation ofDelaware Application May 24, 1933, Serial No. 672,568

2 Claims. (Cl. 61-45) This invention relates to waterproofing masonrystructures, and particularly structures such as subways, cellars,vaults, tunnels, etc., which are of such size and structural character-8 istics that there is likelihood of cracks occurring between differentparts of the construction. It is particularly applicable to thewaterproofing of subterranean structures of concrete,incorporating'steel framework or re-enforcements.

It is necessary in structures of the character described to carefullywaterproof the work so as to prevent, as far as possible, the leakage ofground water into the interior of the structure. Frequently where thework is at some depth below the surface of the ground, the ground waterexerts considerable pressure upon the bottom and sides of the structureand, if there are any openings or cracks whatever, the leakage will besubstantial. It is well known that concrete walls and floors are not inthemselves sufciently waterproof to prevent this leakage, and it isaccordingly customary to apply waterproof coatings of bituminousmaterials such as asphalt with or without layers of fabric, felt, paperor the like. Such asphaltic and bituminous coatings have not provedfully efficacious in practice for the reason that such materials do notpossess any true elasticity, but are really viscous uids. If bituminousor asphaltic compounds are used which are quite soft they may eventuallyflow out entirely from their intended location. On the other hand, ifcompounds-are used which are sufficiently hard not to flow excessively,they will harden further and tend to become brittle when cold and willcrack. 'I'hls is particularly true where there is expansion andcontraction of the structure, or movement of the parts thereof due tosettling of the earth, vibration, etc. As structures of any size arealways subject to these influences, some leakage invariably occurs whereknown methods of waterproong are utilized. A

great deal of difficulty has been experienced from these causes, andlarge sums are constantly being expended in attempting to repairwaterproofing which has failed, in pumping out seepage, and in otherways. These diificulties with the use of bituminous or asphalticwaterproofing coatings are not overcome by the use of fabricre-enforcements in the coating. The fabric may tear if the movement ofthe parts is considerable, but, even if the movement is slight, thebituminous coating will be cracked or disrupted to such an extent as topermit leakage even if the fabric is not torn. Furthermore, if theasphaltic coating is cracked to such an extent as to permit Water toreach the fabric, the latter will rot.

In accordance with my invention, I have overcome these defects inprevious waterproofing coatings by providing a waterproofing coating or5 layer which possesses true elasticity as distinguished from merefluidity, and which will yield, stretch and contract in accordance withthe expansion and contraction or settling of the elements of thestructure, and thereby retain its 10 continuity and effectivewaterproofing qualities under the varying conditions of use.

Another disadvantage of the ordinary bituminous or asphalticwaterprooiings is that they have to be applied hot. This is an expensedue to 'i5 the necessity for heating apparatus at the job, and requiresexpert supervision in carrying out the heating at the proper temperatureso as to avoid danger of overheating or burning the waterproofingmaterial which destroys th'e use- 2o fulness. The heating of theasphaltic materials is particularly objectionable in underground work asthe fumes endanger the health of the workmen. In accordance with myinvention I provide a waterproofing process which, in its pre- 215ferred embodiment, does not require the heating of the waterproofingmaterials, as the preferred materials which I employ may be appliedcold.

As an illustration of a particular application of the invention, thesame Will be described as 30 applied to the waterproofing of a subwayincorporating a steel frame-work and having a iioor, walls and roof ofconcrete.

In the drawing Figure 1 shows a View in perspective, partly broken away,oi' a subway con- 35 struction showing various stages in the buildingthereof.

Figure 2 is a vertical diagrammatic sectional view through the floor ofthe subway construction showing the different layers embodied in a 40preferred example thereof.

Referring to the drawing, a suitable excavation or trench is rst dug,the ground surface at the bottom of the excavation being indicated at l,the side wells ef the trench er excavation if 45 necessary beingprotected by suitable temporary sheathing 2 which is supported by woodenframing 3. If the subway is located under a street a wooden iiooring 4may be laid on the framing 1f desired. on the bottom ef thetrenen e1eyer 50 of concrete I0 is laid which is referred to as the invertprotection concrete. This layer of concrete is also carried up the sidewalls ofthe excavation for a distance, as indicated at Il. A coat ofwaterproofing material is then applied to 55 the concrete and carried upthe side walls far enough to protect the joint between the bottom f andside wall protective concrete, and on this layer of waterproofing one ormore layers of fabric are laid such as burlap or coarse muslin. Afurther coating of waterproofing material is preferably applied over thefabric, so that the fabric and waterproofing compound combine to form awaterproofing layer I2. As the waterproong material, I do not use a hotapplied bitumen or asphalt such as is commonly employed, but in placethereof I use a mix/ture containing rubber latex or other dispersedrubber. This is preferably incorporated with an asphalt or bitumen andthe mixture is of such a nature that it can be applied cold. I prefer touse a mixture cornprising`a water emulsion of asphalt, rubber latex anda ller. As an example of such a mixture and the method of preparing thesame the following may be given;

A bituminous emulsion (mixture A) is first prepared as follows: l

Parts Native asphalt and/or gilsonite 50 Water 50 Protective colloid maynow be Parts Latex (38% rubber) 96 Sulphur (in colloidal form) 1 to 3Shellac (powdered) 2 Sodium benzoate 2 In place of the sodium benzoateother preservatives to prevent destructive fermentation of the latex maybe employed such for instance as ammonia, formaldehyde, phenol, orphenol derivatives, urea, etc. The shellac may be omitted altogether orin place of it some other gum or resin may be utilized such as rosin,manila copal etc. The sulphur is not always necessary, but acts tovulcanize the rubber and thereby renders the coating tougher and morepermanent. Any of the usual accelerators and activators may be added ifdesired. The sulphur by bringing about vulcanization of the rubber alsoacts as a preservative and where it is used, the use of otherpreservatives for the latex-may in some cases be dispensed with.

A mixture is now made comprising about 75 parts more or less of theasphalt emulsion (mixture A) and about 25 parts more or less of thelatex compound (mixture B). A suitable quantity of ller is now addedusually in an amount about equal to the amount of the above mentionedcompound. Also a small amount of sodium silicate is preferably added.For example the following proportions may be utilized:

, Parts Compound having the formula above given- 100 Powdered feldsparor other ller 100 Sodium silicate 1 to 3 The amount of sodium silicatewill vary depending upon the amount of ller used. The filler ispreferably wetted with water prior to incorporating in the compound.

Instead of using a water emulsion of asphalt with the latex incorporatedtherein I may use a, compound comprising asphalt dissolved in a volatilesolvent and having a coagulated latex or dispersed rubber incorporatedtherein. An example of a formula for such compound is as follows:

As an example of a coating compound which I may employ which does nothave' an aqueous vehicle, the following may be given: A solution ordispersion of asphalt in a. volatile petroleum oil is prepared in anysuitable manner. This may be an ordinary solution or dispersion 'ofpetroleum asphalt or native asphalt or it may be a liquid asphalticpreparation prepared as described in the United States patent to McRaeNo. 1,684,593. To this may be added a solution or dispersion of rubberin a volatile solvent. Preferably this solution or dispersion isprepared as follows:

Natural latex derived from Hevea Braziliensis or other rubber bearingplant is treated with a coagulating agent, preferably acetic acid, inorder to obtain the solid material. Other coagulables that may be usedare salts, acids, alcohol, etc. Aiter treating the latex with thecoagulant the aqueous layer is lteredvor drained off and the rubberresidue obtained is dispersed or dissolved in petroleum spirits to aconcentration of approximately rubber. The latex prior to precipitationor solution in the petroleum spirits may have added sulphur up to 3% ofthe rubber content and rosin, manila gum, shellac or other resinssoluble in the mixture.

The rubber solution described is then added to the asphalt solution inthe desired proportion up to a maximum of approximately 50% of the totalvolume. Suitable fillers are now added such as clay, talc, gypsum,feldspar, bentonite, carbon or lamp black, wood flour, asbestos orground cork. Generally speaking, an amount of ller may be utilizedapproximately equal to the amount of the liquid compound.

The above examples are merely illustrative as particular vingredientsand the proportions thereof may be varied. The important characteristicof the waterproofing material is that after it sets or cures it shallpossess a degree of elasticity so that in the event of cracks forming inthe masonry the imperviousness of the waterproofing will not bedestroyed.

Upon the waterproofing layer I2, in the example of subway constructionillustrated, a course of brick and mastic is applied which retains thewaterproofing layer in place during the further construction. Upon thelayer of brick and mastic the main concrete floor I4 of the subway islaid. Supported on the floor I4, or upon suitable piers, are footings I5on which rest the steel columns I6 which support the roof girders I1,each pair of columns land transverse girder I1 constituting a steelbent. Between these steel bents are formed the concrete side wall archesI8 and roof arches I9.v The side walls and roof are waterproofed bymeans of the application of alternate coats of the waterproofingmaterial described and of fabric, a coating of waterproofing compoundbeing rst applied then a ply of fabric and then another coat ofwaterproofing compound and a ply of 'fabric until three or four plies offabric are in place. A waterproofing layer 20 is thus formed coveringthe side walls, and a similar layer 2l covering the roof. The side wallprotective concrete II is carried up over the side wall waterproofinglayer and a roof protective layer of concrete 22 is laid over thewaterproofing on the roof.

The subway is thus seen to comprise a complete box or tube comprising a,bottom Il of concrete, side walls comprising concrete arches I8 andsteel columns I6, and a roof comprising steel girders I1 and concretearches I 9. This construction is completely encased in a waterprooiinglayer comprising an elastic waterproofing compound such as the asphalticand rubber latex compound described, which waterproong compound isreenforced with one or more layers of fabric incorporated therein. Thewaterproofing layers are held in place and protected by a complete layerof protective concrete comprising the invert protection concrete I0,side Wall protection concrete H and roof protection concrete 22. In alarge construction of the character described there is certain to besettling of the earth in places, expansion and contraction due totemperature changes, and severe vibration due to the running of thetrains through the subway. These causes are sure to cause cracks in theconcrete in pla-ces, particularly where the steel bents are located.This will result from the unequal settlement, ex-

pansion or contraction, or vibration oi the bents.

With ordinary asphaltic or bituminous waterproong materials the cracksin the concrete will result in many instances in the formation of cracksin the waterproofing layer, but in my improved method of waterproong thepermanent elasticity of the waterproofing layer will permit such layerto stretch and contract so as to cover the cracks in the masonry withoutthe formation of corresponding cracks in the Waterproofing, and leakageis thereby efectually prevented.

As will be understood, the example of my invention given is merelyillustrative of one preferred embodiment thereof, and my method ofwaterproofing may be applied in a similar manner to the waterproofing ofcellars, or other masonry structures.

I claim:

1. The method of waterproofing masonry structures which consists inapplying cold to the surface of the masonry to be Waterproofed, apermanently elastic waterproong layer comprising a water emulsion ofasphalt having rubber latex incorporated therein, applying fabric oversaid waterproong layer, applying a further waterproong coating over thefabric and laying a protective wall of concrete over said waterproofing.

2. The method of waterproofing subterranean structures during theconstruction thereof which consists in laying a protective body ofconcrete on the bottom of the excavation, applying a permanently elasticwaterproong layer thereon comprising asphalt, rubber latex and avulcanizing agent and one or more plies of re-enforcing fabric, laying amasonry floor on said waterproofing layer, constructing side walls and aroof above said floor, said side wvi/alls and roof being constructed ofconcrete having steel frames therein, applying a permanently elasticwaterproong layer over said side walls and roof, said layer comprisingasphalt, rubber latex and a vulcanizing agent and one or more plies ofre-enforcing fab- Y ric, and covering said Waterproofing layer with aprotective layer of concrete extending over the side walls and roof ofthe structure.

ARTHUR A. JOHNSON.

